(1) Field of the Invention
The present invention relates to an apparatus for detecting a position of an electronic part, which includes, for example, such as resistors, capacitors, ICs and the like, which the apparatus is used when said part after having been removed out of a stick or a part storage space is attracted by attraction means, after which said part is mounted in place on a substrate, such as a printed circuit board.
(2) Description of the Prior Art
Generally, in an automatic mounting apparatus for electronic parts called a mount apparatus for automatically mounting passive elements such as capacitors or semiconductor elements such as diodes, ICs, etc. in place on a substrate, where after said electronic part has been removed out of a part storage space or a stick, the part is transferred by attraction means to a predetermined location on the substrate, it is necessary to detect a position (attitude) of the electronic part attracted to the end of said attraction means (nozzle). As for one example, Japanese Patent Application Laid-Open No. 60-103,700 discloses a system in which a conductor pattern on the print circuit board substrate is subjected to imaging as a pattern image by fluorescence.
Among semiconductor elements, LSIs shown in FIGS. 7 (a) and (b), respectively, that is, LSI called QFP (Quad Flat Package) and LSI called LCC (Leadless Chip Carrier) or PLCC (Plastic Leadless Chip Carrier) have been recently widely used. In the illumination of light (illumination light) merely from one side, the aforesaid QFP involves no problem since a terminal pin 2 is projected from a package body 1. However, in the case of the aforesaid LCC, since a terminal pin 4 is not protruded from a package body 3, imaging by use of a so-called transmission light causes recognition to be very obscure and there is the remotest chance of detecting position.
In the aforementioned prior examples, in the former example, a conductor pattern on a print substrate need be processed into a fluorescent pattern, and in addition, in the case of an electronic part such as the LCC which is not protruded from the package as previously mentioned, it is difficult to perform detection of position, which produces a disadvantage in that a lead terminal cannot be subjected to imaging.